Repercute value on other sheet with auto-detect

Question

So here's my Sheet 1 "Portefeuille" :

My goal is to have it automatically update the K9 cell of Sheet 1 (which also corresponds at Symbole CW8) with the actual value of K9 plus the value placed on H9 in Sheet 2 whenever it detects a new line with Symbole CW8 on Sheet 2.

Can you please help me ?

Answer 1

Try in K9:

=INDEX(IFNA(VLOOKUP(C9:C; Sheet2!B:H; 7; 0)))